Plant Toxins (L12)

Question 1

How do plants defend themselves?

Answer 1

• Physical
• Anima Guard
• Visual
• Chemical

Question 2

Why are some plants poisnous?

Answer 2

• To survive
• Protection/defence from predators
• Could only be harmful to specific things
• Releases chemicals from their roots or fallen leaves so plants cannot grow next to them

Question 3

What is the source of their poisons?

Answer 3

• Certain ecological conditions such as an accumulation of toxic inorganic materials (such as copper, lead, nitrates, manganese)

Question 4

Why have people shifted to phytomedicine?

Answer 4

• Belief that herbal remedies are safe
• Dissatisfaction with conventional drugs
• High price of prescription drugs
• Inflated claims of efficacy of herbal-based remedies
• Erroneous belief that herbal products are superior

Question 5

Which age group are the most likely to be poisoned by plants?

Answer 5

Young children

Question 6

What factors affect toxicity?

Answer 6

• Genetics
• Geography
• Season
• Age/part of plant

Question 7

What are some common poisonous parts of a plant?

Answer 7

• Berries/fruits
• Seeds/flowers/leaves
• Stems/roots/bulbs

Question 8

Some plants can cause skin reactions that could be rashes, inflammation, blisters, etc, what is this known as?

Answer 8

• Allergic or irritant contact dermatisis

Question 9

Name a few toxic plants

Answer 9

• Death cap (Fatal dose = 1 mushroom)
• Hemlock dropwart (fatal dose = 1 root)
• Ackee (fatal dose = 1 fruit)

Question 10

Name a few plants that cause skin reactions

Answer 10

• poison ivy, poison oak, poison sumac - Urushiol oil
• Giant hogweed, stinging nettles
• Dieffenbachia
• Agave

Question 11

name plants can cause gastrointestinal irritation (diarrhoea, vomiting, nausea)

Answer 11

• Amaryllis - bulb
• Buttercup - all parts
• Daffodil - all parts, bulb more potent
• Wisteria - pods
• Mistletoe - berries and leaves

Question 12

Which toxic protein in Castor Bean Plant seeds cause agglutination of red blood cells

Answer 12

Ricin

Question 13

What are the symptoms of ricin poisoning from the intake of castor beans?

Answer 13

• Respiratory distress, severe vomiting, multiple organ failure
• Death within 48-72 hours

Question 14

The beans of the Jequirity Bean plant releases which poison?

Answer 14

Abrin (A chain, B chain)

Question 15

What are symptoms of Abrin poisoning?

Answer 15

• Stomach cramping
• Vomiting and severe diarrhoea
• Can also inc seizures, liver/kidney failure

Question 16

What do both Abrin and Ricin inhibit?

Answer 16

Protein synthesis

Question 17

What are the two major subtypes of Acetylcholine receptors? (AChRs)

Answer 17

• Metabotropic muscarinic receptors
• Ionotropic nicotinic receptors

Question 18

What are acetylcholine receptors?

Answer 18

An integral membrane protein that responds to the binding of acetylcholine, a neurotransmitter

Question 19

Which neurotoxin blocks acetycholine receptors?

Answer 19

Curare
- It binds to acetylcholine receptors at the neuromuscular junction and preventing nerve impulses from activating skeletal muscles - Paralysis.

Question 20

Which neurotoxin is a nicotinic acetylcholine
receptor antagonist that comes from Hemlock?

Answer 20

Coniine - inhibition of the nervous system - causes suffocation in mammals

Question 21

What are the symptoms of coniine poisoning?

Answer 21

Ataxia, salivation, paralysis, heart & respiratory failure

Question 22

Which is deadlier, water or poison hemlock?

Answer 22

Water hemlock, can cause death within a few minutes of ingestion

Question 23

Which toxin comes from water hemlock?

Answer 23

Cicutoxin - acts as a noncompetitive gamma-aminobutyric acid

Question 24

What are the symptoms of cicutoxin poisoning from ingestion of water hemlock?

Answer 24

severe vomiting, gastrointestinal pain, convulsions, dizziness, salivation, etc

Question 25

Which neurotoxin inhibits muscarinic acetylcholine receptors from the ingestion of deadly nightshade?

Answer 25

Atropine

Question 26

What are symptoms of atropine poisoning from the ingestion of deadly nightshade?

Answer 26

Delirium, hallucinations, tachycardia, fever, amnesia

Question 27

G-protein-coupled muscarinic acetylcholine receptors
(mAChRs) can be divided into five subtypes, what are these?

Answer 27

M1-M5

Question 28

Which neurotoxin can competitively inhibit all 5 subtypes of mAChRs?

Answer 28

Hyoscine, which comes from Henbane (part of the nightshade family)

Question 29

Capsicums (part of the nightshade family) toxin capsaicin is otherwise known as?

Answer 29

Mace, causes a burning sensation

Question 30

What is capsaicin an agonist of?

Answer 30

TRPV1 (transient receptor potential vanilloid 1) - capsaicin activates and depolarizes receptors, causing a burning sensation

Question 31

Which neurotoxins come from the plant Strychnine tree?

Answer 31

• Strchynine and Brucine

Question 32

What does Strchynine do to the body?

Answer 32

It is an antagonist of glycine and acetylcholine receptors which is lethal in small doses (30-120mg in adults)

Question 33

What does Brucine do to the body?

Answer 33

Acts as an atagonist of glycine receptors and paralyses inhibitory neurons.

Question 34

What are symptoms of brucine poisoning?

Answer 34

Fatal dose is 1g, symptoms include: muscular spasms, cramps, stiffness, convulsions, hypothermia

Question 35

What is a famous poisoning case to do with strchynine?

Answer 35

Christiana Edmunds - Chocolate cream killer. Injected into chocolates

Question 36

What do cardiac glucosides inhibit?

Answer 36

• Sodium-potassium pump
• Sodium-calcium pump
  Causing increase of intraceullular Ca2+ and Na+

Question 37

Cardiotoxins